The Pittsburgh Pirates have brought back Chris Archer’s sinker, and the jury is still out

After completely abandoning the pitch over the past few seasons, Chris Archer has brought back his sinker in a big way since joining the Pittsburgh Pirates.

When the Pittsburgh Pirates acquired Chris Archer, many felt it to be a natural extension of the club’s movement — albeit glacial — towards a more breaking-ball/high four-seam fastball heavy approach.

Archer certainly seemed to fit this bill, carrying a slider known as one of the best in the game. Archer’s toolbelt also carries a token changeup and curveball. Many wondered how the Pittsburgh Pirates’ brass might tinker with pitch selection and sequencing to maximize his go-to slider.

We should have known all along.

Archer’s sinker/two-seam fastball is back, baby.

What is the purpose?

I heard your audible groan from here, but let’s get one thing right: the sinker/two-seam has a place and a purpose.

This feels like a good time to mention that many pitch recognition data collectors have a hard time distinguishing between a sinker and a two-seam fastball due to similar movements and spin. Players have a similarly difficult time as well. For the purposes of this post, consider a sinker/two-seamer interchangeable.

That purpose is to setup other pitches and induce soft contact. In this way, it actually makes sense that the Pittsburgh Pirates would have Archer resurrect his sinking fastball. The club is investing in Archer’s slider, so why not do everything they can to set it up properly?

I’ll let you draw your own conclusions on that, but here’s mine: I think the answer is somewhere in the middle.

I took a look at the right handers who threw sinkers the most. I then grabbed their pitch sequencing data from Baseball Prospectus to see how often those sinker-heavy pitchers paired the pitch with a slider.

Note: Hendricks does not throw a slider, according to Statcast. His most common pairing with a sinker is another sinker.

From this table, we can see that of these top five sinkerballers, Corey Kluber pairs a slider the most, and it’s not wonder as his slider carries the best weighted on base average against of any of these folks seen.

While the data shown does not pick out wOBA or any other metric on just these pitch pairings, we can reasonably assume that Kluber’s slider gets a boost from the sinker, what with 20 percent of his sinkers followed by a slider and a sparkling WOBA against the pitch overall.

So, again, choose your own adventure on what to believe. Many would think it naive to think that throwing a sinker in front of a breaking pitch would not have some impact at the very least.

Regardless, if Archer is going to use the sinker/two-seam to the degree shown below, we might as well look at it with a critical eye.

Left or right...it doesn’t matter

Since joining the Pittsburgh Pirates, Chris Archer has seen a sharp increase in sinker usage to say the least:

Need a different visual? I got you. Here’s a raw look at Archer’s sinker via strike zone:

There is a lot of hang here. More on that in a second.

But first, let’s comment on just how indiscriminately Archer throws a SI-SL combination.

With the exception of throwing a changeup against same-sided hitters (a big no-no anyway according to most), Archer keeps his pairings pretty even among right and left handed bats. Good to know.

But now, back to that hang. The weird thing about that chart is that Archer has typically had great vertical movement on his sinker:

Though the sample size is maddeningly small (Archer did just start throwing it again after all), I would suspect that his sinker carries a feast-or-famine quality in that it either drops, or does not drop at all.

Take a look at two consecutive sinkers that Archer threw in his last start to Braves’ all-world hitter Freddie Freeman:

Both pitches — labelled as sinkers/two-seamers by Statcast — hung up on the plate. Freeman went on to double in that at-bat, off of a slider no less. But Archer is playing with fire. This sinker/two-seam that missed to Dansby Swanson could have been a ton of trouble:

Swanson popped out. No harm no foul. But if Archer continues to rely on a two-seamer/sinker to setup his slider, the pitch must be better, or else good hitters will take advantage.